Catalytic hydrolysis by synthetic polymers

Kunitake, Toyoki; Okahata, Yoshio

doi:10.1007/bfb0023971

Cited by 75 publications

(24 citation statements)

References 129 publications

(121 reference statements)

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“…This hypothesis is supported by findings that peptide dendrimers rich in histidine, and even nonpeptide polymers containing imidazole moities, can function as esterases. 46,47 The frequent occurrence of heme binding, peroxidase activity, and hydrolase activity in other systems based on the polypeptide backbone and natural amino acid side chains is consistent with our results with binary patterned de novo proteins, and suggests that rudimentary activity is relatively common in the feedstock of evolution.…”

Section: Functional Proteins Occur Frequently In Unselected Librariessupporting

confidence: 89%

Cofactor binding and enzymatic activity in an unevolved superfamily of de novo designed 4‐helix bundle proteins

et al. 2009

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To probe the potential for enzymatic activity in unevolved amino acid sequence space, we created a combinatorial library of de novo 4-helix bundle proteins. This collection of novel proteins can be considered an ''artificial superfamily'' of helical bundles. The superfamily of 102-residue proteins was designed using binary patterning of polar and nonpolar residues, and expressed in Escherichia coli from a library of synthetic genes. Sequences from the library were screened for a range of biological functions including heme binding and peroxidase, esterase, and lipase activities. Proteins exhibiting these functions were purified and characterized biochemically. The majority of de novo proteins from this superfamily bound the heme cofactor, and a sizable fraction of the proteins showed activity significantly above background for at least one of the tested enzymatic activities. Moreover, several of the designed 4-helix bundles proteins showed activity in all of the assays, thereby demonstrating the functional promiscuity of unevolved proteins. These studies reveal that de novo proteins-which have neither been designed for function, nor subjected to evolutionary pressure (either in vivo or in vitro)-can provide rudimentary activities and serve as a ''feedstock'' for evolution.

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Section: Functional Proteins Occur Frequently In Unselected Librariessupporting

confidence: 89%

Cofactor binding and enzymatic activity in an unevolved superfamily of de novo designed 4‐helix bundle proteins

et al. 2009

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“…Lipophilic microdomains have also been occasionally used as catalytic microreactors. In the case of polymer-based systems, examples were reported for different polymer families, namely poly(ethyleneimine) [1][2][3][4][5][6], poly(vinylimidazole) [7][8][9][10][11], poly(vinylpyridine) [12][13] and poly(diallylamine) [14][15][16]. Although the magnitude of the catalytic activity was generally not much higher than that of the parent hydrophilic polyelectrolytes, the presence of hydrophobic microdomains and of catalytic groups was considered as a critical factor to increase reaction rates.…”

Section: Introductionmentioning

confidence: 99%

Deprotective activity of nanosized globular partially quaternized poly(tertiary amine)s in peptide synthesis

Chapon¹,

Coudane²,

Vert³

et al. 2002

E-Polymers

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Bifunctional polybases of the partially quaternized poly Ndiethylaminomethyl)ethylene] type (Q(PTDAE),X, with X = percentage of N-quaternization) are able to catalyze various reactions including lipophilic reagents temporarily entrapped in the hydrophobic core of the globules. In this contribution it is shown that benzyloxycarbonyl (Z) and fluoromethyloxycarbonyl (Fmoc) protecting groups of peptides are cleaved at room temperature in a few minutes in an aqueous medium at pH 7,4. Deprotection was also effective when peptides were attached to solid supports of the Merrifield type provided a hydrophilic spacer arm of the poly(ethylene glycol)-type was inserted between beads and the built up peptide moieties. However, unhooking was observed when the hydrophilic spacerpeptide bond was an ester but not when it was of the amide type. The work shows that Q(PTDAE),X globules exhibit enzyme-like activity in a homogeneous aqueous medium and in heterogeneous systems as well.

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“…[1][2][3][4] Especially, after the discovery of catalytic nucleic acids such as ribozyme and deoxyribozyme, 5,6 the design and synthesis of nuclease mimics, catalyzing the cleavage of DNA or RNA, continue to be an attractive goal in nucleic acid research. In contrast to the enormous study on the activities of natural nucleases, however, only a few nuclease models were proposed.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of the polysaccharide, (1→5)-α-D-ribofuranan and its catalytic activities for the hydrolysis of phosphates and the cleavage of nucleic acids

et al. 2004

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The polysaccharide, (1ç5)-α-D-ribofuranan, was synthesized by a cationic ring-opening polymerization of 1,4-anhydro-2,3-di-O-benzyl-α-D-ribopyranose with the aid of boron trifluoride etherate and subsequent debenzylation. This polysaccharide catalyzed the hydrolysis of ethyl p-nitrophenyl phosphate, uridylyl(3´ç5´)uridine ammonium salt, and 4-tert-butylcatechol cyclic phosphate N-methyl pyridinium. The polymer also catalyzed the cleavage of nucleic acids (DNA and RNA). The hydrolysis of ethyl p-nitrophenyl phosphate in the presence of the polymer was accelerated by 1.5Ý 10 3 times relative to the uncatalyzed reaction. The catalytic activity was attributable to the vic-cis-diols of the riboses being located inside the active center that is formed by polymer chain folding; these diols form hydrogen bonds with two phosphoryl oxygen atoms of the phosphates so as to activate the phosphorus atoms to be attacked by nucleophile (H 2 O).

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Catalytic hydrolysis by synthetic polymers

Cited by 75 publications

References 129 publications

Cofactor binding and enzymatic activity in an unevolved superfamily of de novo designed 4‐helix bundle proteins

Cofactor binding and enzymatic activity in an unevolved superfamily of de novo designed 4‐helix bundle proteins

Deprotective activity of nanosized globular partially quaternized poly(tertiary amine)s in peptide synthesis

Synthesis of the polysaccharide, (1→5)-α-D-ribofuranan and its catalytic activities for the hydrolysis of phosphates and the cleavage of nucleic acids

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